US 12,447,029 B2
Bioerodible magnesium alloy microstructures for endoprostheses
Jonathan S. Stinson, Plymouth, MN (US); Dennis A. Boismier, Shorewood, MN (US); Jacob Drew Edick, Minneapolis, MN (US); Torsten Scheuermann, Munich (DE); Louis Toth, Rogers, MN (US); Jan Weber, Maastricht (NL); and Charles Deng, Chanhassen, MN (US)
Assigned to BIOTRONIK AG, Buelach (CH)
Filed by BIOTRONIK AG, Buelach (CH)
Filed on Jan. 22, 2021, as Appl. No. 17/155,826.
Application 17/155,826 is a division of application No. 15/358,636, filed on Nov. 22, 2016, abandoned.
Application 15/358,636 is a continuation of application No. 14/178,869, filed on Feb. 12, 2014, granted, now 9,603,728, issued on Mar. 28, 2017.
Claims priority of provisional application 61/765,412, filed on Feb. 15, 2013.
Prior Publication US 2021/0137709 A1, May 13, 2021
Int. Cl. C22C 23/02 (2006.01); A61F 2/82 (2013.01); A61L 31/02 (2006.01); A61L 31/14 (2006.01); C22F 1/06 (2006.01)
CPC A61F 2/82 (2013.01) [A61L 31/022 (2013.01); A61L 31/14 (2013.01); A61L 31/148 (2013.01); C22C 23/02 (2013.01); C22F 1/06 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A bioerodible endoprosthesis comprising:
a bioerodible magnesium alloy consisting of magnesium and between 5 and 11 weight percent aluminum, optionally between 0.1 and 3 weight percent zinc, optionally calcium, and optionally between 0.05 and 0.3 weight percent manganese, wherein the alloy has a microstructure comprising equiaxed Mg-rich solid solution phase grains having an average grain diameter of less than or equal to 5 microns and continuous or discontinuous second-phase precipitates in grain boundaries between the Mg-rich solid solution-phase grains, the second-phase precipitates having an average longest dimension of 0.5 micron or less, the bioerodible magnesium alloy including potential impurity elements of less than 200 ppm of each of iron, copper, nickel, cobalt, gold, cadmium, bismuth, sulfur, phosphorous, silicon, tin, lead and sodium.